Stepping relay



Nov. 10, 1959 Filed Jan. 6, 1958 J. HAWKINS STEPPING RELAY 2 Sheets-Sheet 1 lA/VE/VTOP JEAN HAWK/N6 his ATTOP/VE) Nov. 10, 1959 J, HAWKINS 2,912,543

' STEPPING RELAY Filed Jan. 6, 1958 2 Sheets-Sheet 2 fivvzwro JEAN HAWK/NS ay g tw his A TT'OP/VEY 12 543 STEPPI NG RELAY l a i s C be al s nqrtto nn n Rad'o Manufacturing Corporation, San Jose, Calif, a

My invention relates to relays, and particularly to a multiple contact stepping relay. l One off'the" objects of my invention is the provision of a single pole multiple contact relay having its operating- 'part'sfsurrounded by a vacuum'. i

Another object is the provision of a stepping relay having a rotatable contact actuator arm adapted'for intermittent rotation.

A still further object is the provision of a stepping relay having an intermittently rotatable contact actuator arm which rotary movement of the arm is accompanied by its displacement in a direction parallel to the axis' of rdtation.'

another object of the invention is the provision of a rotary stepping relay in which the operating assembl is electrically insulated from the relay contacts.

Another object is the provision of a vacuumstepping relay in which mechanical and electromagnetic means cooperate to effect rotation of the contact actuator arm.

The invention possesses other objects some of which with the foregoing will be brought'out in the following description of the invention. 1 do not limit myself to theshowing made by the said description and the draw ings, since I may adopt'variant forms of the invention within the scope of the appended claims.

Referring to the drawings:

Fig. 1 is a vertical half-sectional view, partly in elevation, taken in a plane indicatedby the line 11 of Fig. 2.

' Fig, 2 is a horizontal sectional view taken in the indicated by the line 22 of Fig. l." a

Fig. 3 is a schematic view illustrating the cooperative relation of the rotatable ratchet wheel teeth with the pawls just before the solenoid is energized to pull the armature and ratchet wheel down.

Fig. 4 is a schematic view similar to Fig. 3, and illustrating the cooperative relation of the rotatable ratchet wheel teeth with the pawls just before the solenoid is deehe'rgized and the armature and ratchet wheel are raised by the spring. I

All'of the figures are drawn to an enlarged scale for the sake'of clarity.

Broadly considered, the stepping relay of my invention comprises an envelope through one Wall of which extend a plurality of contact rods providing terminal leads out side the envelope and resilient displaceable contact points within the'envelope. A main lead extending through the envelope wall provides a main contact within the envelope common to and adapted to be engaged and disengaged by the resiliently displaceable contact points. Means are provided for effecting resilient displacement of the contact points to engage and disengage the common or main contact point. A pulse responsive solenoid is mounted in the envelope wall to provide an energizable coil outside the envelope and a movable armature within the envelope. A ratchet wheel, rotatably supported on the armature and axially movable therewith, carries a replane silient'contact actuator arm which engages and disengages United. States Patent Patented Nov. 10,

the resiliently displaceable contact points. The contact actuator "arm is preferably electrically insulated from the ratchet wheel. I v

The applications and advantages of my relay are many and varied. It'niay be used, for instance, as a remotely controlled'power switch for transferring voltages fro m one source to a plurality of different load circuits. Since contact resistance remains substantially constant over the life of the relay, it may be used with advantage for monitoring metering equipment. A'pluralit y of these relaysmay be grouped and synchronized for operation in conjunction with the taking of a multiplicity of readings from different types of measuring equipment or electronic memory devices. The relay is also useful for antenna or band shifting, transmit-receive switching and frequency shifting in radio frequency applications.

In more specif c terms, the relay of my invention comprises a hollow cylindrical' wall 2, preferably at metal, closed at one end'by an apertured" annular ceramic plate 3', having its outer peripheral edge hermetically brazed within the open end of the cylindrical wa1l 2. At it's other end the cylinder provided with a radially extending annular'flange '4, towhich is hermetically brazed an annular'metallic closure plate 6 as shown. The outer peripheral edges of the'flang'e and plate are preferably heliar'cbrazedhn order to obtain an integralhermetic union whiclrmay be easily opened,'a nd also-to prevent the admission 'of eontaminantsdnto the envelope thus forrmdd.

Extending into the envelope through the central aperture of theannular ceramic plate 3 is a main lead 7. The main lead is'"tub'ular' in formland' is' hermetically brazed to the innermetallized periphery of'the ceramic plate. The open inner end' of the tubular lead'7 is provided with an outwardly extending flange 8,'on the outer peripheral portion of which is brazed a short annular main contact ring'9.' Molybdenum is preferred for this main contact ring because'of its superior arcing characteristics. shown in Fig. 1, the tubular main lead 7- also functions as a tubulation in the envelope evacuation process after which its upper end 11 is crimped as shownto seal the tubulation Y e The integral union of the tube 7 and the ceramic plate is strengthened by a metal washer 12 which is slipped over "the tube so as to lie against the outside surface of the ceramic plate and is then brazed to the tube. The washer also'serves as a base to which a hollow tubulation protective cover or main lead extension 13 may be soldered. A low melting point solder is preferred so as not to disturb the integral nature of the previously brazed joints. A screw 14 in the outer end of the main lead source of electric power.

fExtending through the ceramic wall 3 at circumferem tially spaced intervals is a series of contact rods, each providing an external leadportion 16 extending through the wall 3 parallel to'and radially spaced from the main lead 7. To insure a hermetic union between each contact rod and the end wall of the envelope, each contact extension 13 provides means for connecting the relay to a rod extends through and is brazed to a flanged metallic tending contact point 19. The free ends of the contact pointsextend under the molybdenum contact ringand are lvertic'ally spaced therefrom a small amount. This is the disengaged or open position of the contact points; To effect closing of an electrical circuit through one of;

the contact rods, the corresponding contact point is resiliently displaceable vertically to engage the contact ring 9, which is common to all contact points.

Means are provided to effect displacement of successive contact points. Integrally mounted hermetically within the inner periphery of the closure plate 6 and extending on both sides thereof is a hollow cylindrical steel housing 21. Centrally positioned within the housing is a steel core 22, integrally fixed to the housing by a transverse wall 23 through which the core extends. The transverse wall is non-magnetic, formed conveniently of Inconel, and is brazed at its outer periphery to the housing and at its inner periphery to the core. The transverse Inconel wall thus hermetically closes the inner end of the housing, and positions the core to provide an efficient magnetic circuit. A steel closure plate 24 closes the outer open end of the housing and is demountably secured to the outer end of the core by screw 26. The closure plate 24 thus forms a part of the magnetic circuit, which is energized by a coil 27, fixed on the closure plate 24 and fitting snugly within the space between the core and housing. Coil leads 28, hermetically sealed in the plate 24, are provided for connection to an electric power source.

Within the envelope and integrally fixed on the inner end of the core in axial alignment therewith is a tungsten post 29. The post serves as a slide bearing or journal for the magnetizable and reciprocable armature 31, extending transversely over the inner ends of the core and housing. A bearing sleeve 32 having its lower end integrally brazed to the armature is slidably and rotatably arranged coaxially on the post 29. The armature is normally held in spaced relation to the inner ends of the core and housing by a coil spring 33, interposed between the underside of the armature and the transverse wall 23. When the coil 27 is energized, the armature is pulled down to engage the core and housing and bridge the gap therebetween. The magnetic circuit is thus completed by the armature, which is held in lowered position until the coil is deenergized, at which time the compressed spring 33 moves the armature away from the core and housing.

Rotatably mounted on the armature sleeve 32 is a ratchet wheel comprising a hub 34 journaled on the outer peripheral surface of the sleeve between the armature and a stop ring 35, brazed to the sleeve at its upper end. The hub is provided with integral radially extending spaced plates 36 and 37, having on their outer peripheries two circular series of opposed teeth 38 and 39 respectively. The teeth of each series are of the buttress type, each tooth having perpendicular and inclined working faces with reference to the plane of plates 36 and 37. Each of the downwardly projecting teeth 38 of the upper series 36 has a perpendicular face 41, and an inclined face 42, the latter slanting upwardly and to the left as viewed in Figs. 3 and 4, to intercept theroot of the per-' pendicular face of the next adjacent tooth of the series.

1 The upwardly projecting teeth 39 of the opposed lower series 37 are formed with a perpendicular face 43 and an inclined face 44 slanting downwardly and to the left as viewed in Figs. 3 and 4, to intercept the root of the per pendicular face of the next adjacent tooth of the series.

As shown best in Figs. 3 and 4, the teeth of each series are offset, in relation to the opposed teeth of the other series, by an amount equal to one-half the pitch of the teeth. This positions the crest or land of each tooth of each series midway between the crests or lands of two adjacent teeth of the opposed series. The midpoints of inclined faces 42 and 44 are thus positioned directly opposite the crests or lands of the teeth of the opposed series. I t e As shown in Figs. 1, 3 and 4, the two opposed series of teeth are axially spaced to provide a gap or passage 46 between the crest of each tooth and the oppositely positioned inclined face of the tooth in the opposed series.

4 j The ratchet wheel is conveniently fabricated from hard copper or other nonmagnetic metal having desirable wearing characteristics.

Integrally mounted on the top surface of plate 36 adjacent the hub 34 is a block 47 of ceramic or other suitable dielectric material. The block serves as a dielectric base for a resilient metallic actuator arm 48 adapted to selectively engage and disengage the displaceable contact points 19 to effect their engagement and disengagement with the common contact ring 9. The resilient contact actuator arm is conveniently a radially extending U- shaped strip of nickel-steel turned on its side and having the end of its lower arm 49 integrally united to the block 47. The free end of the upper arm 51 of the U-shaped strip is bent outwardly to provide a short flange 52 constituting a bearing portion adapted to mechanically engage the underside of the contact points adjacent their free ends, as shown best in Fig. l. The contact actuator arm is thus integrally mounted on the ratchet wheel and electrically insulated therefrom by the dielectric block 47.

It will be obvious from the foregoing that the ratchet wheel is subject to axial movement with the armature, which in turn is responsive to the magnetic field established by passage of a current through the coil. Also obvious is the fact that the ratchet Wheel is capable of rotation on the armature sleeve 32.

Means are provided to effect rotation of the ratchet wheel in response to the axial movement thereof. Integrally mounted within the envelope on diametrically opposed sides of the coil housing are a pair of axiaIlly extending metallic rods 53 having integral transverse mutually extending and resilient pawl portions 54. The pawls extend into the ratchet wheel between the two series of opposed teeth and are normally engaged in the lower series of teeth 39 when the armature and ratchet wheel are held in their upper position by the spring 33. The pawls are engaged in the upper series of teeth 38 when the armature and ratchet wheel are held in lower position by the magnetic field of the energized coil. Both of these positions are indicated in full lines in Figs. 3 and 4, respectively.

Axial movement or displacement of the armature and ratchet wheel in either direction effects rotary movement of the ratchet wheel in one direction. From the position illustrated in Figs. 1 and 3, downward movement of the ratchet wheel to the position illustrated in Fig. 4 causes the perpendicular side 43 of a tooth 39 to slide past the pawl 54. When the crest of the tooth has cleared the pawl, the pawl is in position to engage the inclined surface 42 of the opposite tooth 38. Continued downward movement of the ratchet wheel against the stiffly resilient pawl causes the ratchet wheel to rotate to the right as viewed in Figs. 1 and 3, the pawl passing through the gap 46. Rotation of the ratchet wheel will continue until the perpendicular side 41 of the next adjacent tooth 38 engages the pawl. At this point the armature has closed the magnetic circuit and the relay may be held in this position if desired at reduced power. The inherent resilience of the pawls serves to materially lessen the impact shock to the relay when the ratchet wheel comes to rest.

Movement of the ratchet wheel downwardly has also removed the supporting contact actuator arm 48 from beneath an associated resilient contact point 19, thus effecting disengagement of the latter from the common contact ring 9. Coincidently, rotation of the ratchet wheel has caused rotary movement of the contact actuator arm toward the next succeeding contact point. This rotary movement amounts to approximately one-half the distance between adjacent contact points. In this position of the parts the relay contacts are held open by the resilience of the coils 18.

To effect closing of one or more of the next succeeding contact points, the solenoid coil is deenergized, permitting ratchet wheel upwardly to the position shown in Figs. 1 and 3. Upward movement of the ratchet wheel causes the perpendicular side 41 of upper tooth 38 to slide past the pawl until the crest of the tooth clears the pawl. At this point the pawl is engaged by the ascending inclined surface 44 of tooth 39, and continued upward movement of the lower teeth causes the pawl to pass through the gap 46 and the ratchet wheel to again be driven to the right as viewed in Figs. 1, 3 and 4. Rotation will stop when the side 43 of the next adjacent lower tooth 39 engages the pawl. Rotation of the ratchet wheel has thus effected the final positioning of the re silient contact actuator arm 48 beneath the next succeeding contact point, and upward movement has resulted in the resilient engagement of the bearing flange 52 with the resilient contact point 19, which is carried upwardly until it engages the common contact ring 9.

While a relay showing a multiplicity of contact points and one actuator arm has been described and shown, it will be obvious that as many actuator arms may be provided as there are contact points, and that varied 0perational sequences and mechanical arrangements may be provided within the scope of the appended claims.

I claim:

1. A rotary stepping relay comprising an envelope,

' a plurality of contact rods extending into the envelope and providing terminal leads outside the envelope and displaceable contact points within the envelope, a main lead extending into the envelope and providing therein a main contact common to all said contact points and engageable and disengageable by successive displaceable contact points, actuating means mounted on the envelope and including an axially movable armature and a rotatable contact actuating arm within the envelope to actuate the displaceable contact points and an energizable coil outside the envelope, and means operatively connected to the contact actuating arm to rotate the arm to effect engagement and disengagement of successive displaceable contact points with said common main contact.

2. A rotary stepping relay comprising an envelope, a plurality of contact rods extending into the envelope and providing terminal leads outside the envelope and displaceable contact points within the envelope, a main lead extending into the envelope and providing therein a main contact common to all said contact points and engageable and disengageable by successive displaceable contact points, actuating means mounted on the envelope and including a spring-pressed armature axially movable within the envelope and an energizable coil outside the envelope and a rotatable contact actuating arm responsive to axial movement of the armature to actuate the displaceable contact points, and means operatively connected to the contact actuating arm to rotate the arm in response to axial movement of the armature to efiect engagement and disengagement of successive displaceable contact points with said common main contact.

3. The combination according to claim 2, in which the envelope is hermetically sealed and vacuumized, and the terminal lead portion of the contact rods and the main lead are hermetically sealed in one wall of the envelope.

4. The combination according to claim 2, in which the envelope is symmetrical about a longitudinal axis and the contact rods are radially and circumferentially spaced thereabout.

5. The combination according to claim 2, in which the contact actuator arm comprises a resilient metallic strip mounted on the armature for axial movement therewith and having a free end adapted to resiliently engage and disengage successive displaceable contact points.

6. The combination according to claim 2, in which the means operatively connected to the contact actuator arm to effect rotation thereof comprises a ratchet wheel rotatable mounted on the armature and a pawl engaging the ratchet wheel and fixedly mounted within the envelope.

7. The combination according to claim 5, in which the contact actuator arm is electrically insulated from the armature.

8. The combination according to claim 6, in which the ratchet wheel is axially movable with said armature and the fixed pawl cooperates with axial movement of the ratchet wheel to eifect rotary movement of the ratchet wheel.

9. The combination according to claim 8, in which said ratchet wheel includes upper and lower series of opposed teeth and the pawl is operatively interposed be tween the series to be. engaged by the teeth upon axial movement ofthe ratchet wheel.

10. A vacuum rotary stepping relay comprising a vacuumized envelope symmetrical about a longitudinal axis, a plurality of contact rods extending into the envelope and constituting circumferentially spaced terminal leads outside the envelope and radially extending resiliently displaceable contact points within the envelope, a main lead axially aligned with the envelope and extending into the envelope to provide therein a main contact common to all said resiliently displaceable contact points and adapted to be engaged and disengaged thereby, an energizeable magnetic coil mounted on the envelope on the outside thereof, a spring-pressed armature axially movable within the envelope, a resilient contact actuator arm rotatably mounted within the envelope and responsive to axial movement of the armature to actuate the resiliently displaceable contact points, and means operatively con nected to the resilient contact actuator arm to rotate the arm in response to axial movement of the armature to effect engagement and disengagement of the resiliently displaceable contact points with said common main contact.

11. The combination according to claim 10, in which the envelope includes a hollow metallic cylindrical shell hermetically closed at one end by a dielectric plate and at the other end by a metallic plate, said contact rods extending hermetically through said dielectric wall and said magnetic coil being detachably mounted on the metallic plate.

References Cited in the file of this patent UNITED STATES PATENTS 1,295,175 Keith et al. Feb. 29, 1919 1,301,206 Wescott Apr. 22, 1919 1,824,973 Wescott Sept. 29, 1931 2,323,702 Berkey July 6, 1943 2,523,360 Ellwood Sept. 26, 1950 2,528,520 Jackson et al. Nov. 7, 1950 

